Ignition circuit



May 17, 1938. H. B. HO-LTHOUSE IGNITION CIRCUIT Filed Aug. 27, 1954 2 Sheets-Sheet l May 17, 1938.

H; B. HOLTHOUSE IGNITION CIRCUIT Filed Aug. 27, 1934 2 Sheets-Sheet 2 .EZT'ETZTZLT'. WERE/B fioLTHq USE. @44 6 M Patented May 17, 1938 UNITED STATES PATENT OFFICE 46 Claims.

My invention relates to ignition circuits, 'and has to do more particularly with ignition circuits for internal combustion engines, although some aspects of my invention are not limited to ignition circuits, but may be employed in connection with other circuits where an intensified spark or other circuit is desired.

One of the principal objects of my invention is to provide an improved ignition circuit.

Another object is to provide an ignition circuit more effective at low cranking speeds and low voltage conditions as are encountered in cold weather or when the ignition battery has run down to some extent.

Another object of my invention is to provide an accessory in the nature of an added high frequency booster circuit adapted to amplify the output of the regular ignition coil and circuit.

A feature of my invention is the provision of a higher starting output for ignition circuits, but which automatically cuts down as the speed of the engine increases, without the use of cutout contacts or relays.

Another feature of my invention is the improvement of the common and well-known ignition circuit employing the ordinary low frequency ignition coil by the addition of a high frequency booster circuit.

Another feature of my invention is the provision of a high frequency oscillating circuit which is added to the regular ignition circuit, being preferably superimposed on the regular ignition circuit.

Another feature of my invention is the provision of a combination low frequency and high frequency ignition circuit, with the high frequency acting to boost the secondary or ignition output of the ignition coil of the ordinary regular or low frequency circuit.

Another feature of my invention is to utilize a condenser charge and discharge to boost the output of the ignition coil secondary.

Another feature of my invention is the elimination of the low frequency or regular spark at the breaker points, thereby eliminating the pitting of the contacts, and substituting a high frequency sparking across the breaker points, thereby distributing the spark over the surface to eliminate the pitting and resulting also in permitting a greater current flow across the breaker points.

Another feature is the provision of a high fre-- quency oscillating coil unit adapted for application to the distributor head for use as a booster circuit to the regular ignition circuit.

Another feature is the provision of an ignition circuit including a high frequency oscillating coil with said coil carried in a one-piece combination coil housing and distributor cap.

There are other features to my invention, and these will be brought out more particularly in the ensuing part of the specification and appended claims.

For a better understanding of my invention, reference is to be had to the accompanying drawings, in which:

Fig. 1 shows one form of my invention employing a high frequency booster circuit added to the ordinary or regular ignition coil or low frequency circuit.

Fig. 1A is a circuit similar to Fig. 1, but employing a different type of high frequency oscillating coil and dual ignition.

Fig. 2 is a circuit similar to Fig. 1, but with the regular condenser around the breaker points disconnected.

Fig. 2A is a circuit similar to Fig. 2 but provided for dual ignition as in Fig. 1A.

Fig. 3 is another form of my invention along the line of Fig. 2, but with the kick coil 6 eliminated.

Fig. 4 is another form of my invention adapted more particularly for an original installation, instead of as an accessory such as in Figs. 1, 2 and 3, in which I provide a combination low and high frequency ignition coil instead of separate coils as in the previous circuits.

Fig. 5 is a circuit similar to Fig. 4, but with the self-induced transformer or kick coil 6 removed.

Fig. 6 is another form of my invention in which I modify the ordinary low frequency ignition circuit to produce a high frequency oscillating spark across the timer contacts; and

Fig. 7 shows the high frequency coil HF as of Fig. 3, mounted as a unit upon the distributor head and connected in circuits with the ordinary low frequency ignition circuit.

Fig. 8 illustrates a coil and circuit identical with Fig. 7 except that coil is carried in a onepiece housing which also serves as the distributor cap.

Fig. 9 shows a high frequency ignition circuit employing a high frequency coil carried in a onepiece combination coil housing and distributor cap.

Fig. 10 illustrates the high frequency ignition circuit as shown in Fig. 9.

As previously pointed out, my invention may be applied to ignition circuits in various ways. For example, in Figs. 1 to 3 I have shown the high frequency so-called booster circuit applied as an accessory to the regular standard low frequency spark coil ignition circuit with the added apparatus shown to the right of the dotted line. These three circuits are again divided into two classifications, Figs. 1 and 2 employing the impedance coil or self-induced transformer in combination with a high frequency or Tesla coil HF as the added high frequency circuit, whereas in Fig. 3 the kick coil 6 is not employed.

I might point out at this time that in these two types of circuits, those shown in Figs. 1 and 2, where the coil 6 is employed, I am enabled, with apparatus otherwise alike, to provide a higher output to the ignition circuit than in the circuit of Fig. 3. One reason for this is that in Figs. 1 and 2 the coil 6, preferably in multiple with the primary of the coil LF, draws an added amount of current from the battery or other current supply, and thus supplies a greater amount of booster current to the primary 1 and thus through secondary ID to the secondary 4 and the spark plug than in Fig. 3 where the current supplied to the high frequency transformer HF is limited to the amount of current that can pass through the primary 3 of the low frequency induction coil LF. In speaking of low frequency ignition coils I refer to the ordinary coil adapted for low frequency impulses such as are employed in the ordinary single unidirectional spark systems.

Thus, although circuits such as in Figs. 1 to 3 have the advantage of being usable as an accessory or added circuit to ignition circuits already installed, they are not limited to such use, as the circuits may be initially built up in that manner.

However, the circuits of Figs. 4 and 5 are preferably adapted for initial installations rather than additions to existing ignition circuits, in that instead of providing an added high frequency coil HF, I provide a single combination low and high frequency spark coil LH instead of the two coils of the previous circuits. In other words I apply a high frequency primary 1 as the third winding to the low frequency coil instead of a separate coil as in Figs. 1 to 3. Again, the circuits of Figs. 4 and 5 differ in that in Fig. 4 I provide the added initial booster current by the use of a kick coil 6, whereas in Fig. 5 this coil is left out.

In Fig. 6 the inductance I which is part of the high frequency oscillating circuit is not used to boost the output of the low frequency coil by induction as in Figs. 1 to 5, but increases the sparking current output of the spark coil by changing the nature of the discharge across the timer contacts from unidirectional low frequency to a high frequency oscillating circuit.

Referring now more in detail to the circuits illustrated, and referring first to Fig. 1, this circuit provides a so-called booster circuit including the high frequency coil HF and the kick coil 6, a function of which is to increase the secondary output of the regular ignition coil LF by adding thereto the output of the high frequency coil, particularly at slow cranking speeds and the resultant low voltage conditions encountered in winter or when the ignition battery is low.

In this circuit I show the usual regular or low frequency spark coil LF including a primary winding 3 and secondary winding 4 connected through the usual ignition switch 2 to the bat tery I which may be a storage battery charged by a generator 15 ordinarily employed. The breaker 5 is shown as operated by the usual cam, and has a condenser 9 shunting the points to eliminate or reduce sparking. The secondary winding 4 extends to the usual distributor D with connected spark plugs. Thus we would have the ordinary or regular unidirectional low frequency ignition circuit.

To the right of the central dotted lineI show the added high frequency circuit which includes a suitable high frequency coil HF such as a Tesla coil, in which the primary I is connected so as to be acted upon by current through the primary 3 of the spark coil and the breaker point 5. Winding 1 is preferably extended through a condenser 8 to ground G so as to provide a high frequency return path to ground. The grounds are shown at separate points, but it will be understood that they are all connected together in common. The secondary III of the high frequency coil is cut in series between the secondary 4 of the spark coil LF and the distributor arm to amplify the output of the ignition coil LF.

In order to provide more than the amount of current that might be fed to the primary 1 through the primary 3 of the spark coil, I provide a so-called booster coil 6 preferably in parallel with the primary winding 3 so as to supply current to the high frequency circuit above what is supplied through the primary 3. This coil 0, which may also be referred to as a self-induced transformer, and is of a high impedance so as to take its maximum current at verylow speeds of the engine in starting, is designed so as to cut down the current flow therethrough very rapidly with the increase in motor speed and consequent increase in frequency of impulses and voltage increase. This permits the booster coil to function at maximum capacity at the low starting speeds when the additional energy is most needed, and particularly if the motor is cold as in winter, or the battery run down, at the same time cutting the coil out very rapidly as the engine speed increases. In other words, the booster coil functions at maximum capacity at low speeds, but the coil is so constructed that as the motor speed increases and the booster current is not needed, the impedance of the coil rises very rapidly as the impulse frequency increases, and the current consumption of this coil drops to a very low value. However, this characteristic can be varied through a wide range so that the coil may continue to function at all speeds or drop down to practically no functioning at high speeds, as desired.

From the circuits which I have tried out, and from my observations thereof,- although I do not want to be confined to the exact theory of operation, it appears that Fig. 1, for example, operates as follows:

Upon closing of the ignition switch 2 and the next ensuing closure of the timer contacts 5, a circuit is closed from the current supply i through the primary winding 3 of the spark coll LE to ground G, and a multiple path for said current is provided through the kick coil 6 and said contacts to ground. In the meantime the distributor arm has connected with one of the spark plugs and thereafter the timer contacts 5 are opened, interrupting thecircuit through the windings 3 and 6, causinga diminishing field in the cores of these windings. The diminishing magnetic field in the spark coil LF induces a current into the secondary winding 4, and the selfinduced current in winding 3 together with kick coil 6 during its diminishing field charge condenser B. A resulting high frequency oscillating circuit is produced, including the primary winding 1 of the high frequency coil HF, setting up high frequency oscillations in the secondary winding l thereof.

Thus we have a current in secondary winding 4 of the spark coil LF induced from the primary winding 3 thereof, and also an added high frequency oscillating current from the high frequency coil to amplify the current from coil 4. Secondary winding ID in this circuit is in series with the secondary winding 4 and so related as to add its potential and current to the output of the secondary winding 4. Thus we have a combined current greater than any current that could be set up by the regular ignition coil windings 3 and 4 alone.

In the circuit of Fig. 1, the condenser 9 is the regular one ordinarily furnished with the ignition system, whereas the condenser 8 in the high frequency oscillating current is added and preferably of sufficient capacity to effect the desired amplification. In connection with the circuit of Fig. 1, I find that with the high frequency discharge across the timer contacts 5, I avoid the pitting ordinarily present where the single or low frequency spark occurs as in the ordinary ignition system as here indicated to the left of the dotted lines, and by the high frequency discharge across these contacts they are kept clean and smooth, and an increased current flow is permitted over that of the single or low frequency spark, thereby permitting a greater flow of current and supplying a higher voltage and'more current for ignition purposes.

In Fig. 1A I provide dual ignition, and therefore instead of providing the high frequency coil of the Tesla type as in Fig. 1, I provide the Odin type of coil 00, supplying high frequency ignition to the one spark plug from the coil 00, and the regular ignition to the other spark plug from the spark coil LF,

In Fig. 2 I have shown a circuit similar to that of Fig. 1 except that the regular shunt condenser 9 is removed or disconnected, and find that the circuit of Fig. 2 operates more effectively than Fig. 1 in that the loss occasioned by the use of condenser 9 is eliminated, as this is added to condenser 8 and used to induce additional current from primary 1 to secondary Hi. The use of condenser 9 in the ordinary ignition circuit serves to prevent sparking at the timer contacts 5, which sparking, if it occurs, not only effects a deterioration of the contacts, but which sparking also slows down the diminishing of the magnetic field of the spark coil LF which would result in a lower secondary output. However, the use of such condenser 9 results in an energy loss. This loss is eliminated in my circuit of Fig. 2.

Fig. 2A is similar to Fig. 2 except that it provides for dual ignition by the use of the Odin type of coil 00 in place of the Tesla type of high frequency coil HF.

In Fig. 3 I have shown another modified form of my invention in which the kick or booster coil 6 is not employed, but in which the high frequency oscillating circuit is supplied with current only from what flows through the primary Winding 3 of the spark coil LF, whereas in Fig. 2 this high frequency oscillating circuit is supplied with additional current by the shunt circuit of coil 6.

In this circuit of Fig. 3 the booster circuit, which includes the high frequency transformer HF, has its secondary winding I0 included in series with the secondary 4 of the spark coil LF, and where this booster circuit is applied to the ordinary or standard ignition circuit the primary winding 1 of the high frequency coil is connected in series between the breaker points 5 and the condenser 8. Condenser 8 may be employed if condenser 9 ordinarily on the distributor as shown in Fig. 1 is inaccessible. In this case, then, both condenser 8 and condenser 9 would be utilized. However, if condenser 9 is readily accessible it may be connected into the circuit in the same manner as condenser 8, that is, in series with winding 1 and ground, and the latter then is not necessary. If both condenser 8 and condenser 9 are used, condenser 8 is, of course, connected as shown in Fig. 3, and condenser 9 as shown in Fig. 1. Thus, in this case, I employ the discharge of this condenser 8 and provide operating current for the primary winding 1 of the high frequency coil to boost the output of the regular ignition coil LF, whereas in the ordinary circuit this condenser charge and discharge, when the condenser is across the contacts 5 as in Fig. 1, is not utilized.

Thus in the operation of the circuit Fig. 3, the provision of the high frequency circuit in series with the condenser 8 prevents the forming of a concentrated are at the breaker points, as it changes the original low tension spark which concentrates and forms a projection on one point and a crater on the other point of contacts 5 due to the polarizing effect of the unidirectional current, to a high frequency oscillating current which dissipates itself in many finelydivided arcs across contacts 5, and which are of low heat value resulting in less burning of the points. In fact this circuit not only adds to the ignition current output of the low frequency coil LF, but also permits longer life of the timer points 5.

Considering Fig. 4, I provide a combination high and low frequency coil in which the high frequency primary 1, instead of being upon a separate coil as in the previous circuits, is wound in inductive relation to the secondary winding 4 of the spark coil so as to add the high frequency oscillations to the normal ignition output of the secondary 4 of the spark coil. Winding 1 in this case (as in Fig. 5) is preferably wound on the outside of the secondary 4 which is wound over the primary 3. Thus I induce current into the secondary from both the primary windings 3 and l to increase the normal output of this coil. In this circuit I also employ the booster coil 6 preferably connected in multiple to the primary winding 3 of the spark coil and thus amplify the ignition output of the coil over the circuit if the kick coil 6 were not employed.

This kick coil 6, as in the case of the previously described circuits, is preferably so proportioned that on low cranking speeds the coil 6 will draw the maximum current and thus produce the greatest amplification of current output of the ignition coil, but also so proportioned that as the speed of the motor increases, the impedance of coil 6 cuts down the current consumption as the amplified current is not needed.

In this circuit of Fig. 4 I have provided what I call combined low and high frequency induction in the single coil, and produce in effect a combination coil and circuit which embodies low and high speed characteristics not obtainable with the ordinary ignition coil alone or with high frequency alone. As to the so-called kick coil 6, this itself may be designed to secure any desired characteristics. It may be designed to function mainly at slow engine speeds, or in other words at slow breaker speeds of the timer contacts 5, and be automatically ineffective at higher speeds.

It may also be designed to function effectively over the whole operating range of the engine from low through high speeds.

Thus I have found that this circuit of Fig. 4 provides a very effective arrangement for ignition and other purposes as indicated, and particularly when used as an original installation rather than the employment of the high frequency booster circuit as an accessory to systems already installed, of the ordinary spark coil type.

In Fig. 5 I have shown another modified form of my invention with a circuit arrangement similar to that of Fig. 4 except that the kick coil 6 is not provided, and the high frequency primary 1 is supplied with an energizing circuit by current which is fed only from the primary winding 3. In other words, the winding 1 is provided only with the self-induced current generated by the winding 3 to charge the condenser 8 and set up the high frequency oscillations in the circuit including condenser 8, winding 1 and spark gap 5. If desired, the winding 3 in Fig. 5 may have a higher primary value than that used with the standard ignition coils, so as to provide more current for the high frequency primary 1.

Thus in the circuits of Figs. 4 and 5, the secondary or output winding 4 of the ignition c'oil LH is common to both the so-called low frequency and high frequency windings 3 and I, whereas in the previous circuits the high fre quency winding 1 was in a separate unit with its own'secondary winding, as H), connected in series'with the winding 4.

In Fig. 6 I have shown another form of my invention in which I modify the ordinary low frequency ignition circuit so as to eliminate unidirectional low frequency discharge across the timer contacts 5 and supply a high frequency oscillating circuit across these points and change the nature of the discharge across these points.

To this end I use an inductance l in series with the condenser ordinarily employed across the timer contacts, which may be the condenser 8 or 9 referred to in the previous circuits, so that upon interruption of the timer contacts a high frequency oscillating circuit is formed, changing the spark across the contacts 5 from a unidirectional to a high frequency oscillating spark. This eliminates the usual pitting at these contacts and with the high frequency spark distributed over the surface thereof, saves the contacts and also permits a greater current fiow across these contacts because of the distributing arc. Furthermore, this appears to result in a faster diminishing field of the spark coil LF, resulting in a greater output of the secondary 4.

In such a circuit, the values of windings of coil LF, inductance l and capacity 8 and 9 should be such as supply the output desired from the secondary 4. In modifying any ordinary circuit to this extent it is only necessary to connect the inductance 1 between the condenser and ground G, or if in an original installation to employ the required values of windings of coil LF and the shunting inductance and capacity to give the desired input and output.

Referring to the arrangement illustrated in Fig. '7, this employs a circuit arrangement such as Fig. 3, in which the high frequency coil HF is made up as a unit with terminals at its opposite ends between which the secondary winding I is connected, and with a pair of terminals on the casing to which the primary winding 1 is connected. Thus, to apply such a unit HF to an installation, the ordinary lead I6 to the center of the distributor head is removed, the one terminal of the coil HF inserted into the distributor head, and the removed terminal then inserted in the top end of the coil HF. The condenser ordinarily connected across the timer contacts 5, or a special condenser employed if desired, is connected in series with the primary I of the high frequency coil HF to provide the high frequency oscillating circuit as shown in Fig. 3. If it is desired to employ the extra kick coil 6 for added output as in Figs. 1 and 2, such a coil is then suitably connected in circuit with the primary winding 1 as indicated in Figs. 1 and 2. y

In the modification illustrated in Fig. 8 instead of providinga separate encased high frequency coil for mounting on the distributor cap D as shown in Fig. 7, I provide a one-piece housing ll. The structure and the circuit are the same as that shown in Fig. 7, except that the housing I! supports the high frequency coil of the Tesla type and also serves as a distributor cap. The housing H is provided with a top portion I8 similar in shape to the coil housing of Fig. 7, which extends through a constructed neck l9 to a cap 2 I. In this embodiment of my inven tion, the ordinary distributor cap may be entirely removed and the housing I! substituted therefor. The ordinary lead l6 to the center of the distributor head is simply inserted in an aperture in the top of the housing to engage one end of the secondary ll] of the high frequency coil HF. The other end of the secondary is in electrical engagement with the distributor head ll.

Fig. 9 illustrates another modification, wherein I provide a high frequency ignition system employing a one-piece housing 22 for supporting a high frequency coil HF of the Odin type, and also serving as a cap for the distributor. The upper portion 23 of the housing, closed at the top, supports the coil HF, and extends through a constructed neck portion to a cap portion 24. The coil itself includes a primary 1 and a secondary winding ID. A kick coil 6 is utilized in the high frequency circuit as a source of energy for charging the condenser 8 or 9. The coil 6 raises the voltage from the battery I to a high enough value to be effective in the high frequency circuit.

The ordinary ignition coil in use at the present time is mounted on the dash-board with an extended cable lead to the distributor. With this installation there is a considerable energy loss in the secondary which in turn impairs the bperating efficiency of the ignition system. However, in my system with the high frequency coil HF mounted directly on the distributor in the one-piece housing the secondary loss is negligible. Furthermore, this assembly provides for a short lead to the condenser 8 or 9 with the resulting shortest possible primary oscillating circuit. In this arrangement the primary transformer or kick coil 6 may be mounted at any desired distance from the distributor.

The complete high frequency ignition circuit of the arrangement of Fig. 9 is illustrated in Fig. l0. Further, with respect to the description above, this circuit includes the battery I, ignition switch 2, kick coil 6, breaker points and the high frequency coil HF of the Odin type. The condenser 8 or 9 extends to ground 2, and the coil HF is connected with the distributor head H to supply high frequency current to the spark plugs. With the use of the straight high frequency circuit more current may be utilized in the same breaker points than is possible with a low frequency ignition system. This situation exists because the primary oscillating circuit changes the direct current of the battery to oscillating and distributes the sparking over the entire area of the breaker points allowing more current to be used. However, in the flow fre-- quency circuit the current, being unidirectional, concentrates the discharge, making a point on one breaker point and a crater on the other, limiting the sparking to a single point and in turn limiting the current which may be used.

Employing the small high frequency coil HF mounted on the distributor in a one-piece combination housing and distributor cap provides a very inexpensive and sturdy unit. This unit operating in the straight high-frequency circuit described, provides in all a highly efficient low cost ignition system.

Although I have described my invention in its preferred embodiments, it is understood that I am not limited thereby, but limit my invention only by the scope of the appended claims.

I claim:

1. In combination with an ignition circuit including a current supply, spark coil including a secondary winding connected in series with an igniting spark gap and timer contacts, of a booster circuit including a high frequency winding and energizing circuit therefor responsive to control by the timer contacts, said winding being connected to amplify the output of the spark coil.

2. In combination with an ignition circuit including a current supply, spark coil and timer contacts, of a. booster circuit including a high frequency winding and energizing circuit therefor responsive to control by the timer contacts,

said winding being connected in series with a secondary winding of the spark coil to amplify the output of the spark coil.

3. In combination with an ignition circuit including a current supply, spark coil and timer contacts, of a high frequency booster circuit including a high frequency winding and energizing circuit therefor responsive to control by the timer contacts, said winding being connected inductively to a secondary winding of the spark coil to amplify the output of the spark coil.

4. In combination with an ignition circuit including a current supply, spark coil including a secondary winding connected in series with an igniting spark gap and timer contacts, of a booster circuit including a high frequency winding and. energizing circuit therefor energized from said current supply responsive to control by the timer contacts, said winding being connected to amplify the output of the spark coil.

5. In combination with an ignition circuit including a current supply, spark coil and timer contacts, of a booster circuit including a high frequency winding and energizing circuit therefor energized from said current supply responsive to control by the timer contacts, said winding being connected in series witn a secondary winding of the spark coil to amplify the output of the spark coil.

6. In combination with an ignition circuit including a current supply, spark coil and timer contacts, of a high frequency booster circuit including a high frequency winding and energizing circuit therefor energized from said current supply responsive to control by the timer contacts, said winding being connected inductively to a secondary winding of the spark coil to amplify the output of the spark coil.

7. An ignition circuit including a current supply, spark coil including primary and secondary windings and timer contacts controlling said primary circuit; and a high frequency oscillating circuit for amplifying the output of said ignition circuit including a high frequency primary winding, a condenser, and said timer contacts, with said high frequency winding operatively related to the secondary winding of the spark coil.

8. An ignition circuit including a current supply, spark coil including primary and secondary windings and timer contacts controlling said primary circuit; and a high frequency oscillating circuit for amplifying the output of said ignition circuit including a high frequency primary winding, a condenser, and said timer contacts, with said high frequency winding operatively related to the secondary winding of the spark coil, and a kick coil connected between the current supply and the high frequency primary winding and controlled by the timer contacts for supplying added current to said latter winding.

9. A combination low and high frequency ignition circuit including ignition sparking means, a current supply, a low frequency spark coil, and timer contacts interconnected to effect a spark current supply to said sparking means by each operation of the timer contacts; and a high frequency oscillating circuit including a high frequency primary winding, and a condenser, and interconnected with said timer contacts and said spark coil to effect a high frequency oscillating current supply to said sparking means responsive to each operation of the timer contacts.

10. A combination low and high frequency ignition circuit including ignition sparking means, a current supply, a low frequency spark coil, and timer contacts interconnected to effect a spark current supply to said sparking means, by each operation of the timer contacts; and a high frequency ignition supply including a high frequency oscillating coil and condenser included in circuit with said timer contacts and sp .rk coil to effect a high frequency oscillating current supply to said sparking means responsive to each operation of the timer contacts.

11. In combination with an ignition circuit including a current supply, spark coil and timer contacts, of a booster circuit including a high frequency winding connected to amplify the output of the spark coil, and an energizing circuit for the high frequency winding including a kick coil responsive to control by the timer contacts to effect oscillation in the high frequency winding to amplify the output of the spark coil.

12. In combination with an ignition circuit including a current supply, spark coil primary winding and timer contacts connected in series, and a secondary winding for said coil; a high frequency oscillation circuit for amplifying the output of said ignition circuit including a high frequency coil having its primary winding and a condenser connected in series and together con- .nected across the timer contacts and connected to a winding of the spark coil, and a secondary winding for the high frequency coil connected in series with the secondary winding of the spark coil, whereby high frequency oscillations are produced in the high frequency coil responsive to interruption of the timer contacts to amplify the output of the secondary of the spark coil.

13. In combination with an ignition circuit including a current supply, spark coil primary winding and timer contacts connected in series, and a secondary winding for said coil; a high frequency oscillation circuit for amplifying the output of said ignition circuit including a high frequency coil having its primary winding and a condenser connected in series and together connected across the timer contacts and connected to a winding of the spark coil, a secondary winding for the high frequency coil connected in series with the secondary winding of the spark coil, and a booster kick coil having one terminal connected to said current supply and the other terminal to the high frequency series circuit to supply added current thereto, whereby high frequency oscillations are produced in the high frequency coil responsive to interruption of the timer contacts to amplify the output of the secondary of the spark coil.

14. An ignition circuit for internal combustion engines comprising a main ignition circuit including a current supply, spark coil and timer contacts; and a high frequency oscillating circuit for amplifying the output of the main circuit including a high frequency winding connected to amplify the output of the spark coil, and a kick coil connected for supplying energy to the high frequency circuit, the impedance of said kick coil being such as to supply maximum energy at slow starting speeds of the engine.

15. An ignition circuit for internal combustion engines comprising a main ignition circuit including a current supply, spark coil including primary and secondary winding and timer contacts; and a high frequency oscillating circuit energized independently of said secondary coil for amplifying the output of the main circuit including a high frequency winding connected to amplify the output of the spark coil, a kick coil connected for supplying energy to the high frequency circuit, the impedance of said kick coil being such as to supply maximum energy at slow starting speeds of the engine, and to gradually decrease the energy supply as the engine speed increases.

16. In a combination low and high frequency ignition circuit, a main ignition circuit including a current supply, spark coil and timer contacts; and a high frequency oscillating circuit including a high frequency coil winding, condenser and said timer contacts, with connections for superimposing the high frequency oscillating current upon output current of the spark coil of the main ignition circuit in timed relation therewith to amplify the output of the main ignition circuit.

1'7. In an ignition circuit including a low frequency induction spark coil, timer contacts and condenser across the timer contacts, and an inductance included in series with the condenser forming a shunt across the timer contacts, said condenser and inductance being proportioned to effect a high frequency oscillating circuit across the timer contacts when interrupted.

18. In an ignition circuit including a low frequency induction spark coil, timer contacts controlling said coil and a condenser across the timer contacts tending to effect a unidirectional spark across the contacts when interrupted, of means to convert said unidirectional spark into a high frequency oscillating circuit across the timer contacts when interrupted, consisting of an inductance included in series with the contacts and condenser.

19. The system for changing the unidirectional spark across the timer contacts of a conventional type of ignition circuit to a high frequency oscillating spark across said contacts which is characterized by the inclusion of an inductance in series with a condenser across the contacts.

20. A dual ignition circuit including a low frequency induction spark coil and spark plug, a high frequency oscillating circuit and spark plug, a source of current supply, and timer contacts connected in common to said coil and said circuit for simultaneously operating said coil and said circuit to supply corresponding ignition currents to the associated plug.

21. A combination low and high frequency ignition system including a spark plug, means to supply a low frequency sparking current to said spark plug, and means to superimpose on said current a high frequency oscillating current.

22. A combination low and high frequency ignition system including a spark plug, means including a spark coil having primary and second ary windings to supply a low frequency sparking current to said spark plug, and means energized at least in part by the self inductive kick of the spark coil primary winding to superimpose on said current a high frequency oscillating current.

23. An ignition circuit including a spark plug, a high induction spark coil having a high inductance primary winding and a secondary winding for causing a spark at said plug, a source of current and breaker contacts connected in a series circuit with said primary winding, a condenser connected in a circuit across said breaker contacts to absorb energy resulting from self induction in said primary winding when said contacts open, and means in addition to said primary winding connected to said condenser to utilize the energy thus absorbed before it is dissipated by closing of said contacts or by seeping back through said high inductance primary windmg.

24. An ignition circuit including a spark plug, a high induction spark coil having a primary winding of high inductance and a secondary winding for causing a spark at said plug, a source of current and breaker contacts connected in a series circuit with said primary winding, a condenser connected in a circuit across said breaker contacts to absorb energy resulting from self induction in said primary winding when said contacts open, and a primary winding of low inductance connected to said condenser to utilize the energy thus absorbed by inductively boosting the output of said secondary coil.

25. An ignition circuit including a coil of high induction, timer contacts controlling said coil to induce high voltage in a secondary coil, 3. condenser across the timer contacts tending, with said coil, to effect a unidirectional spark across the contacts as a result of opening the contacts, and means to convert said unidirectional spark into a high frequency oscillating circuit across the timer contacts when opened, consisting of an inductance included in series with the contacts and condenser.

26. An ignition circuit including a spark plug, a high induction spark coil having a primary winding of high inductance, and a secondary winding for causing a spark at said plug, a source of current and breaker contacts connected in a series circuit with said primary winding, a low inductance winding connected in a second series circuit with said primary winding which parallels said breaker contacts, means in said second series circuit for limiting the current flow through said low inductance winding to approximately the right value for cushioning the kick of said primary winding, and means for utilizing power developed by said low inductance winding.

27. In combination with an ignition circuit including a current supply, spark coil including a secondary winding connected in series with an igniting spark gap and timer contacts, of a booster circuit including a high frequency winding and energizing circuit therefor, said winding being connected to amplify the output of the spark coil.

28. In combination with an ignition circuit including a current supply, spark coil and timer contacts, of a booster circuit including a high frequency winding and energizing circuit therefor, said winding being connected in series with a secondary winding of the spark coil to amplify the output of the spark coil.

29. In combination with an ignition circuit including a current supply, spark coil including a first primary coil and a first secondary coil, and timer contacts, a booster secondary coil in series with said first secondary coil, and a second primary coil in inductive relation to said booster secondary coil and in series with said first primary coil and a circuit which parallels said timer contacts, and means for preventing the continuous flow of direct current through said second primary winding.

30. In combination with an ignition circuit including a current supply, spark coil and timer contacts, a high frequency booster circuit including a high frequency winding and energizing circuit therefor responsive to control by the timer contacts, said winding being connected inductively to a secondary circuit of the spark coil to superimpose high frequency characteristics on the output thereof.

31. An ignition circuit including a current supply, spark coil including primary and secondary windings and timer contacts controlling said primary circuit; and a high frequency oscillating circuit for amplifying the output of said ignition circuit including a high frequency primary winding, a condenser, and said timer contacts, with said high frequency winding operatively related to the secondary Winding of the spark coil, and an induction coil effective to cause added current to be supplied to said high frequency oscillating circuit.

32. As an accessory for amplifying the output of ignition systems having the usual spark coil, distributor head, timer contacts and condenser across the contacts, a high frequency oscillation transformer unit having a secondary coil having a terminal end for insertion in the top of the distributor head, and a second terminal for connection with the output terminal of the secondary winding of the spark coil, and a primary winding having a pair of terminals on the unit for connection to the condenser and the timer contacts for providing the primary oscillating circuit for the high frequency transformer.

33. An ignition circuit including a spark plug, a high induction spark coil having a high inductance primary winding, and a secondary winding for causing a spark at said plug, a source of current and breaker contacts connected in a series circuit with said primary winding, and means in addition to said primary winding connected in a series circuit therewith independent of said breaker contacts to cushion the kick produced when said contacts open, and to utilize the energy of said kick independently of said primary winding.

34. An ignition circuit including a spark plug,

a source of sparking current for said spark plug connected in series with said plug and effective to produce a given high voltage, and inductive means for boosting said voltage between said source and said plug.

35. An ignition circuit including a spark plug, a sourceof sparking current for said spark plug connected to said plug and effective to produce a given voltage, and inductive means for boosting said voltage between said source and said plug. said inductive means including a low inductance secondary coil connected in series with said source of sparking current and said plug, and means for inducing a high voltage in said secondary coil.

36. An ignition system including a low frequency type transformer with primary and secondary windings, and a high frequency transformer with primary and secondary windings with said transformers connected in a manner such that the primary winding of the high frequency transformer is energized from the primary winding of the low frequency transformer, and the secondary winding of the high frequency transformer is in series relation with the secondary winding of the low frequency transformer.

37. An ignition system including a low frequency type transformer having a primary winding energized by a primary circuit and a secondary winding, means for interrupting the primary circuit, and means for amplifying the output of said transformer in electrical connection with said interrupting means, said amplifying means including a condenser and a high frequency winding in series and together connected across said interrupting means.

38. An ignition system including a low frequency type transformer having a primary winding energized by a primary circuit and a secondary winding, means for interrupting the primary circuit, and means for amplifying the output of said transformer in electrical connection with said interrupting means, said amplifying means ineluding a condenser and a high frequency transformer having primary and secondary windings with said high frequency primary winding and said condenser in series and together connected across said interrupting means, and with the high frequency secondary winding connected in a boosting relationship to the low frequency secondary winding.

39. In an ignition system including a low frequency transformer having a primary winding energized by a primary circuit and a secondary winding, interrupting means for the primary circuit, and a condenser across said means for receiving a charge from said low frequency primary winding, a high frequency transformer having primary and secondary windings with the primary winding in series with said condenser to receive a charge from said condenser and induce a current in the high frequency secondary winding, with said high frequency secondary winding in series with the low frequency secondary winding to add the power output of the high frequency transformer to the power output of the low frequency transform-er to provide a high power output from said ignition system.

40. An ignition circuit including a current supply, a low frequency transformer including pri mary and secondary windings, a high frequency transformer including primary and secondary windings, with the two secondary windings connected in series with one another, means for effectively energizing the two primary windings, and a distributor in series with the high frequency secondary winding.

41. An ignition circuit including a current supply, a low frequency transformer including a p'imary winding energized by a primary circuit and a secondary winding, circuit interrupting means in the primary circuit, a high frequency transformer including primary and secondary windings, with the two secondary windings connected in series with one another, and said ignition circuit including means for producing oscillations in said high frequency primary winding at least at the instant following the operation of said circuit interrupting means, and said transformers acting together to produce a power output which neither one alone could produce.

42. In an ignition system having a low frequency transformer with primary and secondary windings, circuit interrupting means for the primary winding, and means for superimposing on the output of the transformer a current having high frequency oscillating characteristics, said means including a high frequency transformer having a winding in series connection with the secondary winding of the low frequency transformer.

43. An ignition system including a coil having primary and secondary windings, means for interrupting the primary circuit, a condenser in electrical connection with said interrupting means adapted to be charged upon the interruption of said primary circuit, and means, exclusive of said primary winding, in electrical connection with said condenser, including a transformer for utilizing said charge in said condenser to perform useful work therewith in said ignition system.

44. An ignition system including a coil having primary and secondary windings, means for interrupting the primary circuit, a condenser in electrical connection with said interrupting means adapted to be charged upon the interruption of said primary circuit, and means, exclusive of said primary winding, in electrical connection with said condenser, including a transformer for utilizing said charge in said condenser to perform useful work therewith in said ignition system, and with said transformer electrically connected with said coil.

45. An ignition circuit including a spark gap, a source of sparking current for said gap connected to said gap and effective to produce a given high voltage with low frequency characteristics, a high frequency Winding connected in series between said source and said gap and connected by capacity across said gap to form a high frequency oscillating circuit which superimposes high frequency characteristics on said sparking current.

46. An ignition system including a low frequency type transformer having a primary winding energized by a primary circuit and a secondary winding, means for interrupting the primary circuit to induce a voltage in the secondary winding and incidentally produce a kick voltage in the primary winding, and an auxiliary primary winding connected in series with the first named primary winding to receive the kick voltage therefrom and be energized thereby, said auxiliary primary winding operating to boost the output of said secondary winding.

HARRY B. HOL'IHOUSE. 

